Sanderlings are just about eight inches long from beak tip to tailfeathers and weigh in at a whopping 3.5 ounces! These tiny toasted marshmallows are super-zippy as the skitter along the surf’s edge. I as very impressed with the AF tracking speed of the 100-400mm as I may have already mentioned! 1/3200 F6.3 ISO 500 at 500mm.